1. Field of the Invention
The present invention relates to liquid level measuring devices, and more particularly to a device having a collapsible frame along which a float (or floats) is moved by the buoyant forces of the liquid being measured.
2. Description of the Prior Art
In the prior art, it is known to measure the level of a liquid in a container by means of a device having a rigid elongated frame, a buoyant float movable along the frame, and a manually operable means for selectively holding the float in a fixed position relative to the frame so that the frame and float can be withdrawn from the liquid and a visual reading obtained from the position of the float with respect to scale indica on the elongated frame. For example, such devices are disclosed in the William F. Fling, et al U.S. Pat. Nos. 3,638,492 and 3,793,884.
The present invention is directed to a liquid level measuring device having various improvements to the known devices exemplified by applicant's prior U.S. patents. One problem involved in prior devices was that they have rigid elongated frames for mounting the flexible guide cables and floats. The devices would be difficult to store in a compact manner and would be unwieldly should the user wish to transport the devices from place to place. These storage and transport problems would be aggravated where the device is twelve or more feet long as required in many installations. Moreover, the accuracy of the prior art devices exemplified by the applicant's prior patents was dependent upon the accurate securement of the float relative to the frame prior to and during withdrawal of the device from the liquid being measured. Thus, it is desirable to have accurate and reliable means for securing the float to the flexible guide means the user desires to withdraw the device from a liquid.